Road signs convey important information to the driving public every day. Road sign insignia can indicate speed limits, exits, services and other messages helpful to drivers. Unfortunately, not all road signs communicate accurate or pertinent information. Events such as road repairs and improvements often render a sign's message irrelevant or invalid due to the construction activity. The construction activity dictates the sign's removal or concealment until the activity is finished.
Road construction crews typically remove road signs during construction projects scheduled to last for a year or more. For construction projects scheduled to last for a few months, road crews typically just cover road signs rather than incur the added expense of removing or changing the inappropriate sign. Unfortunately, a majority of the concealment schemes employed by construction crews are destructive to the sign.
One popular method of covering a traffic sign is to bolt a sheet of plywood to the insignia side of the sign. Bolts disfigure the sign when driven through both the plywood and the sign's sheet metal face. Workers secure the bolt in place with a nut and washer combination on the backside of the sign. Initially, bolted plywood may effectively conceal the sign, but plywood, when exposed to the weather tends to warp and crack. Untreated plywood is also prone to decay and rot. Warped, cracked or rotted plywood may eventually break free of the bolts and detach from the sign. In addition to plywood's vulnerability to weather, it is a considerably dense material requiring several crewmembers to attach the wood to the sign.
Bolting similar sized signs to the insignia side of a traffic sign is another method of concealing a sign. The method entails securing the insignia side of a similar sized sign to the insignia side of the traffic sign so that only the blank sheet metal side of each is showing. This procedure not only injures the traffic sign to be covered up but also leaves a bolt hole through the covering sign. While this procedure may employ the use of a more durable material than wood, the procedure is also twice as destructive and more expensive.
Other less expensive and less permanent measures have been utilized in an attempt to cover up the insignia side of a sign. Plastic or burlap bags can be placed over the signs. To hold the bags in place workers often use an industrial tape such as duct tape. Such measures rarely last as the elements quickly tear away at the plastic or burlap covering. Soon only a partially shrouded sign and duct tape is all that is left of the sign covering after a few weeks.
A sign covering is needed that is both nondestructive and resistant to the elements. The covering should also be lightweight and easily installed. A successful cover must also be relatively inexpensive and simple to use.